Not content to relegate a historic figure to a partisan punch line, Trump is poised to build on a shameful legacy of betraying indigenous Americans. He is breaking a solemn promise to forever safeguard ancestral lands that speak to vital parts of our country’s history.

That formula increasingly defines the Trump agenda. It strikes at the very ideals of equity and government by the people that sustain our notions of nationhood. In this case, it also revives an acutely painful injustice to the original American people. Wresting land from tribes was disgraceful in the 19th century. We’re not about to countenance it now.

During Monday’s White House ceremony to honor the heroism of the Navajo code talkers—who used their native language as the basis for a secret code that helped the U.S. Marines prevail in some of the bloodiest fighting in World War II—Trump used the occasion to scorn Senator Elizabeth Warren, calling her “Pocahontas.” He managed in a single blundering stroke to offend the dignity of the event, mock Warren’s claim to Native American heritage, and belittle a woman of great importance in our nation’s history.

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“Pocahontas is a real person . . . not a caricature,” Navajo Nation President Russell Begaye told CNN. “This is a person, a young lady and Native American woman, that played a critical role in the life of this nation.”

Much of what is believed about Pocahontas comes from the accounts of English settlers. Captain John Smith wrote in his memoirs that she twice saved the first permanent English settlement in America, at Jamestown. According to accounts by him and others, Pocahontas spent much of her life trying to bridge the conflicting transatlantic worlds of her native Powhatan people and the English invaders.

It is documented that she was the first Native American known to have married an Englishman. She gave birth to the first English-American child of record. And she crossed the Atlantic to bolster flagging investor support in London for the foundering English colony in Virginia. Without Pocahontas, by the settlers’ own telling, Jamestown would have failed.

It’s bad enough Trump doesn’t know history. His plans, now, have echoes of one of the most shameful chapters in our past.

The lands of southeastern Utah have been home to indigenous peoples for thousands of years. It’s a majestic region of sandstone canyons, desert mesas, forested highlands, and red rock formations. One area in particular, named for twin buttes that resemble the ears of a bear, contains ancient cliff dwellings, rock art, and more than 100,000 other archaeological, cultural, and spiritual sites. They attest to varied and diverse American civilizations that existed long before the first Europeans arrived.

Remember, this is public land, protected in the public interest―and in this case, with a twist. The indigenous people whose ancestors lived on Bears Ears lands have a direct say in the monument’s management and long-term planning. The Bears Ears Inter-Tribal Coalition is made up of leaders from the Hopi Nation, Navajo Nation, Ute Mountain Ute Tribe, Ute Indian Tribe of the Uintah Ouray, and the Pueblo of Zuni. It makes sense to tap into the wisdom and experience of people who’ve known these lands for centuries.

Native peoples have a voice, and we all have a stake, in the lasting preservation of Bears Ears. That’s why, since Trump first hinted at carving up Bears Ears, more than a million public comments have poured in to support this unique monument.

If history is the conversation we have with the past, we need to listen closely. Trump, though, is listening to industry’s version, not the American people’s. Well, he won’t get away with it. The Antiquities Act of 1906 gives presidents the authority to designate national monuments. It does not empower them to slice up monuments designated by others. If Trump tries to do that to Bears Ears, we and others will take him to court.

And we’ll carry with us the inspiration of patriots like Peter MacDonald, who was 15 years old when he volunteered to become one of the 400 Navajo code talkers serving our country. Today, he’s one of 13 still alive to tell their story. “What we did truly represents who we are as Americans,” MacDonald said at Monday’s White House ceremony. “We have different languages, different skills, different talents, and different religion. But when our way of life is threatened, like the freedom and liberty that we all cherish, we come together as one.”

And we will come together as one in the next few days, with our community partners, to block any illegal attempt by this president to eviscerate protections for Bears Ears.